A female U.S. Marshal fought back and held a man for police after he groped her and pulled down her pants while running in the North Side of Pittsburgh Tuesday, Pittsburgh police said.

According to the police report, the incident happened on a trail running parallel to River Avenue in the North Side.

Investigators said the U.S. Marshal was off-duty at the time and was jogging when Robert Flynn ran up behind her, placed his hands on her buttocks and pulled down her shorts.

At that point, the marshal told police she chased Flynn toward Anderson Street, while identifying herself as a U.S. Marshal. Officers said Flynn continued to run onto River Avenue and around apartments located on Anderson Street.

Officers said she followed Flynn to a stairwell where he was attempting to hide. When she cornered him, police said, Flynn charged toward her. At that point, investigators said the marshal feared for her safety and fought back, kicking him in the groin and punching him in the face. She held Flynn there while waiting for police to arrive.

When Pittsburgh officers got to the scene, an officer asked Flynn what his last name was and according to the complaint he responded, “Johnson.”

“I asked his first name,” the criminal complaint stated. “Flynn again replied in a very low voice, ‘I don’t know my first name.’”

At that point the responding officer told Flynn he would be finger printed and identified at the jail and he became compliant, investigators said.

The criminal complaint went on to say, “I asked Flynn if he was willing to provide his side of the incident. Flynn stated,’I plead the fifth.’”

The marshal hurt her finger in the fight with Flynn and took herself to UPMC Mercy Hospital for treatment.

Flynn is facing multiple charges, including aggravated and indecent assault.

Pittsburgh police spokeswoman Sonya Toler said Flynn may have also been involved in another incident in the 200 block of Isabella Street near Allegheny Landing around 8 a.m. Tuesday.

Investigators said a woman reported that man lifted up her skirt and ran off toward the river, Toler said.